Centrifugal machine



y 1934. A. o. AUSTIN 1,959,850

CENTRIFUGAL MACHINE Filed Nov. 26. 1930 Fig.1

Fig.5

INVENTOR wwvgy ATTORNEY atentecl May 22 1934 siren STATES PATENT OFFICE CENTRIFUGAL MACHINE Jersey Application November 26, 1930, Serial No. 498,394

20 Claims. (Cl. 210-63) This invention relates to centrifugal separators, and particularly to machines for separating liquid from solid material.

One object of the invention is to provide a centrifugal separator or filter which will be continuous in its operation.

Another object is to provide a machine of the class named which may be charged and discharged while the centrifuge is rotated.

A further object of the invention is to provide a machine of the class named which shall be of improved construction and operation.

Other objects and advantages will appear from the following description.

The invention is exemplified by the combination and arrangement of parts shown in the accompanying drawing and described in the following specification, and it is more particularly pointed out in theappended claims.

In the drawing:

Fig. l is a vertical, sectional View of a centrifugal machine embodying one form of the present invention.

Fig. 2 is a fragmentary, horizontal, sectional view on line 2-2 of Fig. 1.

Fig. 3 is a fragmentary elevation of a modified construction.

Fig. 4 is a horizontal section on line 44 of Fig. 3. V

Fig. 5 is a bottom plan view of a detail.

In centrifuging machines, it has heretofore been customary either to stop or slow down the rotating cylinder to discharge the material which remains in the cylinder after the liquid or molten material has been thrown olf. This is a decided disadvantage as the machines are. usually run at a high speed and considerable energy and time are required to bring the rotating parts up to speed, and slowing down to eject a charge requires a dissipation of energy through braking or other means.

Where the rotating mass has to be alternately started and stopped, there is a tendency to make the rotating parts light in order that the time of the operating cycle may be kept small and as little-energy wasted as possible. With the present invention it is not necessary to slow down or stop the rotating mass for loading or unloading, so that time is not consumed in bringing the machine and material up to an efiicient very high speeds. Increasing the rotating mass of the machine itself also has the advantage that any slight unbalancing due to the charge will have less effect upon the center of gravity of the total mass than Where the unbalanced portion of the charge is greater compared to the total rotating mass.

The invention has many advantages, and may be used both for a continuous filter and a centrifuging machine. As a centrifuging machine, the invention may be used for separating oil from chips, removing excess molten metal as in galvanizing processes, or for any other purpose where a centrifuge may be used. As a filter, the machine has a distinct advantage as a continuous filter may be readily provided, discharging the remaining portion without slowing down the machine. This may be used for many purposes for which a filter or filter press is used, as to separate excess water from clay compositions, to remove molasses or syrup from sugar or separate liquid from crystals. There are several forms which the invention may take.

In the form of the invention shown in Fig. 1 a chamber 35 is provided for the charge to be centrifuged. A charging tube 11 connects with this chamber. In operation the centrifuging chamber rotates together with drums 31. The charge to be centrifuged divides in the chamber 10, a part being thrown outwardly against each drum 31. The drums 31, together with the chamber 35, are carried upon the spindle l4 and rotated thereby, the spindle being driven by a pulley 15 and belt 16 attached to any convenient drive 17. If desired the pulley may be replaced by a direct connected motor, turbine or other suitable driving means. The rotation about the axis 14 furnishes the necessary centrifugal force to separate the liquid from the solid portion of the material to be centrifuged. The charge fed down through the tube 11, preferably by some uniform feeding mechanism, enters the chamber 35 and as soon as the mass acquires rotation, it is deflected to either one or the other of the drums 31. Any unevenness in the charge can be taken care ofby the spring supports'lS which may be blocks of rubber or other resilient material or by a flexible housing, such as is commonly used in centrifuging machines. By properly proportioning the parts, it is possible to balance the load as the deflecting. wedge 19 will tend .to deflect the material to the side having the least load. It will be understood that the yielding supports 18 will permit the frame to tilt toward the side having the greatest load. This will shift the position of the tongue 19 relative to the spout 11 so that more of the charge will fall into the side of the container having the lightest load, thus automatically restoring balance. This is particularly true where the downward mass is given considerable velocity. The drums 31 are larger in diameter at their middle portions than at their ends and are provided with radially projecting, longitudinally extending ribs 20, which may be curved circumferentially as shown in Fi 2.

In operation the charge of material is thrown against the surfaces of the drums 31 and any liquid material in the charge will tend to flow along the inclined surfaces of the drums toward their ends. The solid material is prevented from flowing off by friction or by the bafiles 20, or both, depending upon the nature of the material. The liquid flows to the ends of the drums 31 and by virtue of the centrifuging force is thrown outward and caught by the guard channels 21, enclosing the outer edges of end plates 22 on the drums. The plates 22 are perforated to permit the liquid to pass to the outer surfaces thereof. The guard plates 21 discharge downwardly through a spout 26. The solid material remaining on the face of the drums will be held in position by the centrifugal force. By rotating the drums, however, the charge of material can be brought to a point where it will fly off into any suitable catching device.

Where the machine is used for removing excess molten coating material in galvanizing work, the pieces may be allowed to strike directly in a quenching liquid at some little distance. As the speed will be uniform, it will be comparatively easy to figure out the path of travel. This will prevent adhering of the parts together, which is one disadvantage in machines where a large part of the material is dumped at one time into a quenching medium. Where the center of gravity of the charge is at one side of the axis of the drum, there will be a tendency to rotate the drums 31, so all that is necessary in discharging the load is to control the speed of rotation of the drums on their axes. This may be done in several different ways, some of which will be described later. V The invention provides a continuous centrifuging or filtering operation and includes means for controlling the rate of discharge and the time under which the material is centrifuged. In addition, means are provided for balancing the unequal load. During operation of the machine, it is not necessary to slow down the rotating mass 'and all of the various elements may be readily controlled. Since the mass does not have to be started and stopped intermittently, the rotating mass may be rather large without interfering with the power consumed. Since the operation may be made continuous, the size of the centrifuging machine may be rather small compared to one of the intermittent types. If desired, the machine may be shielded so as to re ducewindage losses or operated in a vacuum or a gas considerably lighter than air. v

The control of the pressure inside of the case or the chemical nature of the gas may have certain very material advantages. Where the scheme is used for removing excess water from clay or 'colloids, the partial vacuum will tend to further dry the material and, at the same time, reduce any windage losses. Where the chemical nature of the gas is controlled this may have important advantages in preventing oxidation or the discoloration of the material in the centrifuge. This is a particular advantage where the cylinder '38 with the baffles 39.

the centrifuge is used for coating materials with tin, zinc or other materials. The lowered pressure and control of the chemical composition of the gas also tend to permit the material to stay hot longer without additional heat. If desired, hot gases may be passed down through the charging tube 11, as shown in my prior application, Serial Number 8,826. With the continuous machine the parts may attain a working temperature amply high to permit efficient separation of molten metal from the solid portions. In starting up the machine, however, it may be desirable to heat the parts and provide necessary gases to control the temperature. If the heating gases are of a reducing nature, oxidation may be prevented, which will be a distinct advantage in some cases. By the control of the speed of centrifuging, the rate of discharge of the drums and the temperature of the charge, the thickness of the coating may be closely controlled. The continuous machine has the advantage that 'all parts treated are given approximately the same treatment.

7 Although I have shown the drums tapered toward their ends, they may be tapered in the opposite direction if a proper discharge path is provided for the fluid. In such a case the fluid will discharge into the drum on the inside and then pass to the opposite side, and from thence to the ends of the drum and out. Where the drums are perforated or consist of screens, the fluid will find an easy passage regardless of the form of the drums. It is generally advisable, however, to provide some form of shield and a discharge point so that the liquid will take the proper discharge path and splashing will not occur.

In the form of the invention shown in Figs. 1 and 2, drums 31 are carried on vertical spindles 32 journaled in a frame 33 carried by the spindle 14.. The frame 33 is provided with an upper plate 34 which supports the charging chamber 35 having imperforate side walls 30, together with end drums 31 and deflectors 36. The purpose of the deflector plates 36 is to cause the charge to accumulate at one side of the axes of rotation of the drums. This will tend to cause the drums 31 to rotate in the direction of the arrows. An automatic braking device may be used which will permit the rotation of the drum when the torsional moment exceeds "a certain value. Such a device is shown at 37. The rotation of the drum. is prevented by a frictional device 37 which will permit slipping when the drum accumulates a charge sufficient to cause the necessary unbalanced load. If desired the release of this device may be controlledby external means so that the releasing and charging can be controlled at will.

Another means for controlling rotation of drums 31 is shown in Figs. 3 and '4 which show a releasing mechanism that will permit rotation of the drums with a definite unbalanced load and without the uncertainty of friction. With an arrangement of this kind, it is possible to balance the load on each unloading drum separately. I A cylinder 38 with closed ends and internal baffles 39 is attached to the shaft '32 so that the rotation of the drum 31 will rotate By placing some material which will flow, such as sand, 'water or shot, inside the cylinder 38, it is possible to make "the vanes 39 pick up a load of the ma"- terial as the drum rotates in the direction of the arrow due to the imbalanced load on the its lit

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drum. The baffles or vanes 39 form pockets with the sides and ends of the cylinder so that as they rotate a given amount of the counterbalancing charge is picked up and as rotation of the drum continues, the material picked up will be carried inwardly until it is released by the vanes, when it will again be discharged to the outside. The torsional moment set up by the counterbalancing material will depend upon the amount of material off-center and the effective torque arm. The unbalanced load can readily be controlled by changing the dimensions of the retarding drum. If material is used other than a liquid or fluid, the friction and angle of piling up may be sufiicient to provide the necessary unloading force. Where a fluid is used, however, it is necessary to use battles or vanes which will provide an unbalanced load.

In certain classes of work, it may be detrimental to holdthe material on the unloading or filter drums beyond a given time as would be occasioned if for anyreason the charging was stopped. The device, however, may be arranged to prevent this and permit of the gradual unloading regardless of whether or not there is an unbalanced load. This may be brought about by providing small openings 40 in the vanes or bafiles 39 which will permit the leaking out of the unbalanced medium used in charging the retarding device. Any suitable material such as water, oil or mercury may be used or, if desired, sand, punchings or other material can be used to advantage. In general, however, there would be little or no wear in connection with a fluid as against the use of solid material in any form. This arrangement has the advantage that different unbalanced loads may be provided for and the device will automatically tend to discharge a heavier load. It, of course, is evident that 1 many schemes may be provided which will be automatic in the release of an unbalanced load when this reaches a given value.

The arrangement of the bafiies, general contour of the charging tube and chamber 35, together with the unloading drums, will, of necessity, depend upon the material. These drums may be concave, if desired, straight or of any shape best adapted to the material. The solid material leaving the drums is discharged into a chamber 41 which may be of any convenient form. By utilizing the tangential force, it is usually possible to allow this material to discharge in any convenient location. If desired, sweeps 42 may be attached to the framework for clearing out the material. Where a device of this kind is used for clearing off excess material of galvanized or tinned articles, the material may be allowed to discharge and fall directly into a quenching medium so as to avoid abrasion. If desired, the temperature and nature of the gas inside of the chamber may be controlled along the lines previously stated.

Instead of operating continuously, the invention may be operated upon a batch basis. For

i this mode of operation it has a material advantage over the ordinary centrifuge or filter in that it is not necessary to slow down the rotating parts to charge or discharge the container. Where the machines are used for removing excess water, as in filtering clay or other materials, the air current set up may be used to advantage in carrying off vapor. Where the charge is retained a considerable time in the centrifuging apparatus, the amount of water or liquid removed by the centrifuging operation and by evaporation may give the desired result. Where suitable controls are provided for the discharge devices, the invention is suitable for this mode of operation as well as for continuous operation.

I claim:

1. A centrifugal machine comprising a rotatable support, a drum mounted to rotate bodily with said support and also to rotate about its own axis spaced from the axis of said support, said drum having pockets in the periphery thereof, means for directing material into the pockets at one side of the plane determined by the axis of rotation of said drum and the point on the periphery of said drum nearest the axis of rotation of said support, said drum having passages for the escape of liquid from the surface thereof and being rotatable by the centrifugal force on said material to discharge the mate rial from said pockets, and means for resisting rotation of said drum said resisting means being arranged to yield to a predetermined torque on said drum.

2. A centrifugal machine comprising a rotatable container, said container being rectangular and closed at two opposite sides, means for directing material to the other two opposite sides of said container when said container is rotated, said container having passages in said last named sides for permitting escape of material from said container, and means for controlling the escape of material from said passages to permit separation of the constituents thereof by centrifugal action. 3. A centrifugal machine comprising a rotatable container closed at two opposite sides and having passages for the escape of material from the other two opposite sides thereof, drums rotatably mounted in said passages for intercepting the escape of material said drums having passages for permitting the escape of liquid from the intercepted material, the drums being rotatable to control the discharge of the residue from said container.

4. In a centrifugal machine, a rotatable container, a rotatable member for controlling discharge of material from said container, and a counterbalance device for controlling the rota-' tion of said member.

5. In a centrifugal machine, a rotatable container, a rotatable drum having pockets in the outer face thereof for controlling the escape of material from said container, and a counterbalance device having internal pockets supplied with a counterbalancing medium for controlling the rotation of said drum.

6. In a centrifugal machine, a rotatable container, a rotatable member for controlling the escape of material from said container, said member being actuated by the centrifugal force on said material, and a brake for controlling the rotation of said member.

7. A centrifugal machine having a rotatable part provided with a surface for retaining a charge, said surface being tiltable relative to the axis of rotation of said part for discharging material from said surface, and means to limit the tilting of said surface tocause discharge of all material from said surface in excess of a given amount, said means being operable to prevent tilting of said surface when less than said given amount is held thereby.

8. A centrifugal machine having a rotatable support provided with two surfaces for retaining charges on said support balancing against each other, said surfaces each being tiltable relative to the axis of rotation of said support to discharge material from said surfaces, and means for limiting the tilting of said surfaces, said limiting means being arranged to be overcome by force exerted by material on said surfaces for discharging all of the charge from each surface in excess of a given amount to maintain said charges in approximately balanced relation.

9. A centrifugal machine comprising a rotatable support provided with surfaces for retaining balanced charges, said surfaces being movable for discharging from each of said surfaces an excess of said charges beyond a predetermined amount to maintain a balanced relation, and means for resisting movement of said surfaces to retain the predetermined amount thereon, said resisting means being arranged to permit discharge of all of said charges under certain conditions.

10. A continuous filter comprising a rotatable member having a surface from which the material tends to discharge, a retarding device for said material, said retarding device being movable to control the amount of material held by said surface, and automatic means dependent in its operation upon the amount of material on said surface for regulating said retarding device to determine the amount of material on said surface.

11. A continuous filter comprising a rotatable support having filter surfaces for retaining balanced charges, from which surfaces the material tends to discharge, a retaining device for said material, means for controlling the operation of said retaining device to prevent discharge of a predetermined amount of said material, said controlling means being arranged to release said retaining device to permit discharge of all of said material within a limited time in case no additional material is fed to said machine.

12. A centrifugal machine comprising a rotating container having means for charging material to the interior thereof and for separating the material into balanced portions, and means operated by the centrifugal force on said balanced portions for dscharging excess of said portions over a predetermined amount to maintain the balance of said portions.

13. A centrifugal machine comprising a rotating container having means for charging material to the interior thereof, means for separating said material into balanced portions, discharge drums for controlling the escape of said portions from said machine, said drums being rotated by the centrifugal force on said portions, and means for controlling the rotation of said drums to permit discharge of the material of said portion in excess of a predetermined amount to maintain the balance of said portions.

14. A centrifugal machine comprising a rotatable container, means for charging material to said container, and means operated by the centrifugal force of an unbalanced charge in said container for directing the material charged to said container into position to restore the balance of said machine.

15. A centrifugal machine comprising a rotatable container, a yielding support for said container to permit displacement of said container under the force of an unbalanced charge in said container, means having a discharge opening. for charging said container, and a deflector in said container arranged to'be shifted relative to the discharge opening by the displacement of said container by the unbalanced charge for directing the material charged to said container into position to counteract the effect. ofthe unbalanced charge and restore the balance thereof.

16. In a centrifugal machine, means actuated by centrifugal force for discharging material from said machine, and meansactuated by cen trifugal force for controlling the operation of said discharge means.

17. The combination with. a centrifugal machine, of rotatable means having a surface for retaining material in said machine, the centrif ugal force on the material in said machine exerting a torque on said retaining means tending to rotate said means, and centrifugal means for controlling the rotation of said retaining means.

18. A centrifugal machine comprising a container mounted to rotate about-an upright axis, a yielding support for said container arranged to permit the axis of said container to shift'laterally under the influence of an unbalanced load in said container, means for directing material into said container in line with the axis of rotation of said container when said axis is vertical, .a divider projecting upwardly in the center of said container for dividing the charge and deflecting it to opposite sides of said container, said divider being movable with said container so that when the axis of said container is shifted by an unbalanced load, said divider will shift to one side of said directing means and will direct a greater portion of the charge toward the side of the, container away from the direction in which the axis is shifted, thus tending to restore the balance of the container.

19. A centrifugal machine comprising a container mounted to rotate about an uprightaxis, said container having a discharge passage at one side thereof, a drum for closing said passage, said drum being rotatable upon an upright axis and having passages to permit escape of liquid from material in said container, means for directing material in said container against the surface of said drum at one side of the plane determined by the axes of rotation of said drum and said container, and means for resisting rotation of said drum but permitting rotation thereof when the force exerted by the material on the surface thereof exceeds a predetermined amount.

20. A centrifugal machine comprising a container mounted to rotate about an upright axis, said container having a discharge opening at one side thereof, a drum for closing said opening, said drum being mounted to rotate about an upright axis and having passages for the escape of liquid from said container, means for directing material from said container against the surface of said drum at one side of the plane determined by the axis of said drum and said container so that centrifugal force on said material tends to rotate said drum, and means for resisting rotation of said drum,.said resisting means comprising a shiftable counterbalance connected with the axis of said drum and operated by centrifugal force to resist rotation of said drum.

ARTHUR O. AUSTIN. 

